AT32UC3A3256 Atmel Corporation, AT32UC3A3256 Datasheet - Page 492

• Manufacturer Part Number: AT32UC3A3256
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A3256

• Flash (kbytes): 256 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 32
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 110
• Ext Interrupts: 110
• Usb Transceiver: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 2
• Uart: 4
• Lin: 4
• Ssc: 1
• Sd / Emmc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 16
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 128
• Self Program Memory: YES
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.0 to 3.6
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 18
• Input Capture Channels: 12
• Pwm Channels: 12
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

23.9.3
Name:
Access Type:
Offset:
Reset Value:
• EXP: SMBus Timeout Clock Prescaler
• THMAX: Clock High Maximum Cycles
• TLOWM: Master Clock Stretch Maximum Cycles
• TLOWS: Slave Clock Stretch Maximum Cycles
32072G–11/2011
31
23
15
7
Used to specify how to prescale the TIM and TLOWM counters in SMBTR. Counters are prescaled according to the following
formula
Clock cycles in clock high maximum count. Prescaled by SMBTR.EXP. Used for bus free detection. Used to time T
NOTE: Uses the prescaler specified by CWGR, NOT the prescaler specified by SMBTR.
Clock cycles in master maximum clock stretch count. Prescaled by SMBTR.EXP. Used to time T
Clock cycles in slave maximum clock stretch count. Prescaled by SMBTR.EXP. Used to time T
SMBus Timing Register
f
prescaled SMBus
,
30
22
14
6
SMBTR
Read/Write
0x08
0x00000000
=
EXP
f
------------------------
2
CLKTWIM
(
EXP
+
1
)
29
21
13
5
28
20
12
4
TLOWM
THMAX
TLOWS
27
19
11
3
-
26
18
10
2
-
LOW:SEXT
LOW:MEXT
25
17
9
1
-
.
24
16
HIGH:MAX
8
0
-
.
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